Giant kelp can grow more than a foot per day. The slimy seaweed doesn’t require land, fresh water, or fertilizer like other energy-producing crops (think corn, for one). Now scientists are testing a way to grow kelp on a large scale for use as a biofuel.
Kelp, a subgroup of seaweed, is the world’s largest species of marine algae. This algae type can grow up to 175 feet tall. Kelp features long stems, called “stipes,” and flowy, wide blades or leaves.
People have harvested kelp for food for thousands of years. Rich in vitamins, minerals, and antioxidants, this dark leafy green gets labeled a “superfood.” Today, it shows up in products from shampoo to ice cream.
From the 1940s-90s, researchers experimented off and on with algae-based fuels. But the low cost of oil always won out over the expense of making fuel from seaweed.
However, rising oil prices have spurred renewed interest in algae as an energy source. Biologists, oceanographers, and engineers work with scuba divers, research technicians, and students to study seaweed.
Kelp usually grows in shallow zones near a coastline—where sunlight and nutrients are plentiful. However, that location poses a problem for boats, beachgoers, fishers, and others.
The area needed to grow enough kelp to replace other fuels would need to be 100 times the size of Utah according to Cindy Wilcox. She is co-founder and president of Marine BioEnergy, a seaweed farm company. Thankfully, God has provided an underwater lab many times larger than that. Researchers figure that producing enough kelp to power all U.S. transportation would use only a fraction of the U.S. coastline.
BioEnergy hopes to utilize submarine drones to cultivate seaweed in the ocean depths. That’s because the top layer of the open ocean has much sunlight but few nutrients. Deeper layers have abundant nutrients but no sunlight.
Future kelp farms would contain rows of seaweed with floats attached. Underwater solar-powered drones would raise a whole farm up on a structure called a “kelp elevator.” The kelp would soak up sunlight in the day and then submerge at night for nutrients. Drones could also drag a farm out of the path of a storm or passing ships. At yield time, drones would pull the farm to a harvesting location.
The BioEnergy team tested kelp’s response to the up-and-down lifestyle. The elevator kelp grew better than kelp kept at one depth.
Ocean plants could someday lessen the need for biofuel crops such as corn and soybeans. Those use up farmland and fresh water. Kelp’s future as a biofuel may burn bright.